1. Field of the Invention
The present invention relates to surface samplers. More specifically, the present invention relates to two dimensional and three dimensional surface samplers for biological particles.
2. Background of the Invention
In today's world, there has become an increased interest and understanding in contaminants that rest or reside on surfaces of virtually everything that comes into contact with humans. These include contaminants on food or counter surfaces, door handles, shopping cart handles, and countless other surfaces which are frequently in contact with human hands or bodies. Such contaminants are typically biological in the form of viruses or bacteria or other harmful particles. To that effect, a number of surface sampling procedures have been developed to test for contamination and other surface pathogens that may be present on a variety of surfaces.
Most conventional surface sampling has been conducted using swabs, wipes or cloth. In some instances, filter material is used for swabbing. Most result in a sample that is picked up on a moistened surface and must be extracted into a liquid for analysis.
In most common tests, cotton swabs (e.g., Q-tips) are used to sample the surface, then the swabs are placed into a tube. Next a conventional procedure is followed to recover particles from that sample into a liquid. Once in liquid, there is an attempt to identify what is collected from that surface via analysis through viable culture, PCR or other methods.
Although such conventional techniques are useful, they are not without their problems and limitations. There are a number of problems with conventional techniques, a main problem being a very limited surface sample. Further, the removal efficiency is low from certain surfaces, and the results are also very dependent on how careful the user is in terms of swabbing the surface.
Further common testing techniques include use of a sponge, or sponge-type surface sampler. The sponge is used to swab the surface, and is about a few inches in diameter so it allows the collection from a larger surface area. The sponge may be used dry or wet. In some techniques, there is a bottle associated with the backside of the sponge which squeezes the liquid through it and draws the collected particles out from that surface and typically into a collection sample bottle, which is then sealed for transport and analysis. One of the primary disadvantages of this sponge technique is that there is lower efficiency from recovering the particles from the surface using the sponge and lower efficiency for recovering the particles back out of the sponge (which naturally has cells in which particles may imbed within). Again, like the swab method, there is a lot of potential variability due to how the user does the extraction from the surface and the extraction from the sponge.
Other conventional techniques used for surface sampling include a large and heavy pressure washing system using a showerhead-like wand which sprays a liquid from a center nozzle and then collects the liquid in a ring of apertures around a peripheral surface of the wand. The jet from the surface is allegedly able to remove particles from the surface which are then drawn up through a vacuum port which goes into the collection container. Although with its advantages, the spray system is extremely heavy (approximately 200 pounds), and is difficult to move freely, and is dependent on the volume of liquid sprayed onto the surface and subsequently collected by the vacuum.
What is needed is an efficient and effective system, device, and method to test the two or three dimensional surface of virtually any object, and subsequently collect the samples from the surface in a manner which produces high concentration of surface sample product. The system, device, and method should be simple to use and administer, inexpensive to manufacture, and effective at collecting and sampling from any surface.